Patent GB-896381-A (GB)
Title: Method and apparatus for automatically determining the listening habits of radio receiver users
IPC: H04H1/00
Filed: 1958-06-30
Abstract: 896,381. Radio receiving arrangements. NIELSON CO., A. C. June 30, 1958 [July 9. 1957], No. 20913/58. Class 40(5). [Also in Group XIX] In a system providing a record of the programmes received by a radio receiver as a function of time, means are also provided for recording, on the same record medium and at periodic intervals or whenever the condition of the receiver is altered, the size of the audience thereto. The size of the audience may be measured by a counter circuit actuated by switches arranged in the door-way of the room in which the receiver is situated or a camera may be provided which photographs the audience either at regular intervals or whenever the condition of the receiver is altered or whenever a person enters or leaves the room containing the receiver. In a first embodiment, Fig. 1, switch-operated pads 20, 21 are placed on opposite sides of the door of the room containing the receiver. A person entering the room closes switch 20 thereby operating relay 41 so that when switch 21 is closed a pulse of current is sent through the "add" coil 46 to move the wiper arm, setting switch 47 in an anti-clockwise direction. Similarly when a person leaves the room he actuates the switch 21 before actuating switch 20, this resulting in a pulse of current being sent through the "subtract" coil 48 and the wiper arm of the setting switch 47 is rotated clockwise. The position of the wiper arm of the switch 47 thus provides an indication of the number of persons present in the room and this is recorded on photographic film by means of a recorder 32 similar to that described in Specification 819,524. In this arrangement a continuously rotating member in the commutator switch 33 continuously samples the electric signals present on the conductors of the cable entering the switch 33; when a high potential output is obtained this operates through the amplifier 35 to light the lamp 36 thus producing a mark upon the film, the position of the mark being determined by an apertured disc 37 which is driven in synchronism with the continuously rotating member in the switch 33. In order to prevent cumulative errors the motor 65 closes switch contacts 63 once per day at a time when no one is likely to be present in the room so completing a circuit through the subtract coil 48 and rotating wiper arm 50 clockwise until the wiper arm of an auxiliary switch 60 reaches the right-hand switch position corresponding to a count of zero. The remaining apparatus, Fig. 2 (not shown), for recording the operating and tuning condition of the receiver on the same length of film comprises essentially the apparatus disclosed in Specification 819,524. Alternatively, Fig. 3 (not shown), each chair in the room being monitored may comprise a switch in its seat, the number of switches being closed thus indicating the number of persons present in the room and this number being recorded on a recorder similar to that shown in Fig. 1. The number of persons present in the room may alternatively be detected by apparatus sensitive to infra-red radiation emanating from the persons in the room, Fig. 4 (not shown). Fig. 5 illustrates a system in which a periodic photographic record is made of persons within the viewing angle of the television receiver. The closure of the operating switch of the receiver 109 actuates relay 115 and also commences driving a motor to rotate the cam 123 so that periodically, e.g. once every five minutes, the relay 120 is actuated to complete the circuit of a solenoid 133 and lamp 102. This causes an exposure to be made by the camera 101 of the scene illuminated, preferably with infra-red light, by the lamp 102. An inclined screen 156 is arranged in front of the camera; the upper portion of this is transparent and thus permits the scene in the room to be photographed, while the lower portion is silvered to permit a record of the time shown by clock 105 and the tuning condition of the television receiver as shown upon indicator 106 to be recorded on the film. The indicator 106 comprises a plurality of lamps which are selectively lit in accordance with the setting of a switch 141 mechanically coupled to the tuning element of the receiver. The apparatus also comprises a "privacy control" 103; this constitutes means whereby when switch 144 is momentarily depressed the camera is prevented from operating for the next half-hour. The operation of switch 144 causes self-holding relay 135 to be actuated thus breaking the circuit to the solenoid 133 and lamp 102. At the same time it completes the circuit of a motor 150 which drives the cam 151 to complete a revolution once every half-hour, at the end of which period the switch 148 is closed to short circuit the relay coil and cause the holding contacts of the relay to open. Furthermore in order that the photograph taken of the viewing area of the receiver may not be too detailed means for diffusing the picture produced upon the film may be provided. Thus the camera could be operated in an out of focus condition or a diffusing screen may be arranged behind the lens of the camera or alternatively the upper half of the screen 156 may be slightly frosted. Fig. 9 illustrates an arrangement in which a photograph is taken only when a person enters or leaves the room containing the receiver or when the condition of the receiver itself is altered. Alternation of the condition of the receiver causes switch 165 to be closed momentarily while a person entering or leaving the room causes switch 166 forming part of the pad 167 to be similarly momentarily closed. This energizes solenoid 171 to pull down rod 174 in a dashpot 175 so that a roller 177 linked to the rod 174 by a pivoting arm passes over a hump formed in a movable switch contact 178. When the switch opens and the rod 174 is released the roller in returning depresses the switch arm 178 against the contact 179 since the arm 176 is prevented from pivoting by the collar 183. Hence the solenoid 133 and lamp 102 are energized, the energization however being delayed with respect to the operation of the switches 165, 166 to permit the person initiating the energization to reach a position within the viewing area of the receiver. Specifications 823,361, 847,596 and 850,075 also are referred to.